Photonique hautement efficace sur silicium : interactions non-linéaires ultrarapides sur puce dans le cadre d'analogies aux horizons des événements optiques [High efficient silicon photonics: on-chip ultrafast nonlinear interactions at an optical event horizon]Problem statementNonlinear interactions between linear waves and solitons have attracted a tremendous amount of interest in the scientific community for many years. In this framework, interactions between waves of similar group velocities particularly draw the attention of researchers for their potential useful applications such as frequency converters or for future optical transistor-like devices. In this particular process, the propagation of an intense solitonic pump in a Kerr medium induces a moving refractive index perturbation, which in turn leads to a frequency conversion of a weak probe wave through a cross-phase modulation process. Since this interaction take place in a dispersive medium, the frequency conversion of the probe in the spectral domain alters the velocity of the probe that is either accelerated or decelerated, preventing any crossing between the two waves. Recently, this effect has been reinterpreted as the optical analogue of the event horizon of black and white holes, as the intense pulse constitutes a horizon that light can neither join nor escape. These so-called optical event horizons have thus also largely been studied for their analogy with general relativity and in particular with the Hawking radiation. Numerous experimental and theoretical studies have been investigated, in various configurations. However, owing to the essential role played by the dispersion properties of the structure for the observation of an optical event horizon, almost all these demonstrations have been performed in photonic crystal fibers (PCFs), for which quasi on-demand dispersion properties can be engineered. On the other hand, silicon integrated nanophotonic waveguides have already proved their great potentialities in nonlinear optics, as for instance, for the supercontinuum generation. Moreover, their fully CMOS-compatible structures, make these structures very promising for high efficiency, low cost and low power useful applications.The aim of this project is to demonstrate such optical event horizon interactions and their related effects in silicon nanophotonic waveguides. Contributions' First demonstration of an optical event horizon in integrated structure by the interaction of an intense pulse and a low power CW probe.' Demonstration of an optical event horizon in silicon nanophotonic waveguide by the interaction of an intense pulse on a cross-polarized CW probe. The very different dispersion properties of the two polarizations lead, among others, to a higher conversion efficiency.ContactDr. Charles Ciret (Charles.ciret@ulb.ac.be)Prof. Simon-Pierre Gorza (sgorza@ulb.ac.be) [Problem statementNonlinear interactions between linear waves and solitons have attracted a tremendous amount of interest in the scientific community for many years. In this framework, interactions between waves of similar group velocities particularly draw the attention of researchers for their potential useful applications such as frequency converters or for future optical transistor-like devices. In this particular process, the propagation of an intense solitonic pump in a Kerr medium induces a moving refractive index perturbation, which in turn leads to a frequency conversion of a weak probe wave through a cross-phase modulation process. Since this interaction take place in a dispersive medium, the frequency conversion of the probe in the spectral domain alters the velocity of the probe that is either accelerated or decelerated, preventing any crossing between the two waves. Recently, this effect has been reinterpreted as the optical analogue of the event horizon of black and white holes, as the intense pulse constitutes a horizon that light can neither join nor escape. These so-called optical event horizons have thus also largely been studied for their analogy with general relativity and in particular with the Hawking radiation. Numerous experimental and theoretical studies have been investigated, in various configurations. However, owing to the essential role played by the dispersion properties of the structure for the observation of an optical event horizon, almost all these demonstrations have been performed in photonic crystal fibers (PCFs), for which quasi on-demand dispersion properties can be engineered. On the other hand, silicon integrated nanophotonic waveguides have already proved their great potentialities in nonlinear optics, as for instance, for the supercontinuum generation. Moreover, their fully CMOS-compatible structures, make these structures very promising for high efficiency, low cost and low power useful applications.The aim of this project is to demonstrate such optical event horizon interactions and their related effects in silicon nanophotonic waveguides. Contributions' First demonstration of an optical event horizon in integrated structure by the interaction of an intense pulse and a low power CW probe.' Demonstration of an optical event horizon in silicon nanophotonic waveguide by the interaction of an intense pulse on a cross-polarized CW probe. The very different dispersion properties of the two polarizations lead, among others, to a higher conversion efficiency.ContactDr. Charles Ciret (Charles.ciret@ulb.ac.be)Prof. Simon-Pierre Gorza (sgorza@ulb.ac.be)]